Oil cooling system for compressors



Ha -hm Oct. 6, 19 59 DAVEY 2,907,515

OIL COOLING SYSTEM FOR COMPRESSORS Filed May 8, 1958 2 Sheets-Sheet lFIG.|

INVENTOR.

PETER DAVEY BYW ms ATTORNEY Oct. 6, i959 P. E. DAVEY 2,907,515

OIL COOLING SYSTEM'FOR COMPRESSORS Filed May 8, 1958 2 Sheets-Sheet 2FIGS INVENTOR.

PETER a. DAVE-Y H \S ATTORNEY United States atent O OIL COOLING SYSTEMFOR COMPRESSORS Peter E. Davey, Fern Creek, Ky., assignor to GeneralElectric Company, a corporation of New York Application May 8, 1958,Serial No. 733,991

3 Claims. (Cl. 230-58) The present invention relates to an oil coolingsystem for hermetically sealed compressors and is more particularlyconcerned with an improved lubricating and oil cooling system for asealed motor-compressor unit mounted with drive shaft axis horizontal.

In accordance with the present invention there is provided a hermeticcompressor comprising a sealed casing having an oil sump in the bottomof the casing and a horizontal axis motor-compressor unit springsuspended within the casing above the sump. In order to limit tilting ofthe compressor unit within the casing, there are provided upper andlower brackets secured to the casing above and below the motorcompressor unit and and having an oil inlet communicating with the sump.

A conduit extending from the pump and connected to the upper tubularelement provides means for circulating a portion of the lubricant fromthe pump to the top of the casing where it is evenly distributed overthe side walls of the casing by means of a baffle and screen arrangementextending between the tubular element and the casing walls. An outletprovided in the conduit connecting the pump with the upper tubularelement is adapted to direct a portion of the circulating lubricant intoheat exchange relationship with the motor means for returning thisportion of the lubricant to the oil sump primarily includes the lowertubular element. In order that the warm oil or lubricant returning tothe sump will first be mixed with cool lubricant or oil flowing down theside Walls of the casing, a partition is provided in the sump betweenthe lower tubular element and the oil inlet to prevent direct flow ofthe returned motor cooling oil to the oil inlet.

For a better understanding of the invention, reference may be had to theaccompanying drawings in which:

Fig. 1 is a vertical view, partly in section, of a hermetically sealedmotor-compressor unit employing the oil cooling system of the presentinvention;

Fig.2 is an enlarged sectional view of the portion of the unit shown inFig. 1;

Fig. 3 is a vertical sectional view taken substantially along line 3-3of Fig. l; and

Fig. 4 is a top view of the unit of Fig. 1 with a portion of the sealedcasing removed to indicate certain details of the battle and screenarrangement of the present invention.

With reference to the drawing and more particularly to Figs. 1 and 3thereof, the disclosed embodiment of the present invention includes asealed casing 1 containing a horizontally disposed motor-compressor unitincluding driven by the motor 2 through a shaft 4. It will be understoodof course that this type of compressor unit is adapted to withdrawrefrigerant from the evaporator component of a refrigerating systemthrough the case 1 and to discharge compressed refrigerant from thecompressor 3 to the condenser component of the system.

The motor-compressor unit is suspended within the casing 1 by means of aplurality of tension springs 5 having their upper ends secured to thecasing 1 and theirv lower ends secured to the motor-compressor unit asshown in Fig. 3, it being understood that there will normally beprovided a pair of such springs at each end of the motor compressorunit. With this type of suspension, means must be provided forpreventing undue tilting of the motor compressor unit either duringshipment or under a heavy shock and for this purpose there are providedupper and lower brackets 7 and 8 which are secured to the casing, eachof the brackets having apertures 9 and 10 therein for receiving tubularelements 12 and 13 respectively secured to the upper and lower surfacesof the housing 14 closing one end of the motor 2 between the motor andthe compressor 3. These tubular elements 12 and 13 are of substantiallysmaller diameter than the apertures 9 and 10 so that the compressor ispermitted to move within limits as supported by the springs 5. n Inaccordance with the present invention the tubular elements 12 and 13 inaddition to preventing excessive tilting of the compressor also formpart of the oil-circu- More specifically the motor cooling and lubricantcooling system comprises an oil pump 18 which maybe of the general typedisclosed and claimed in Patent 2,724,548Bixler issued November 22, 1955and assigned to the same assignee as the present invention. By means ofthis oil pump, oil is withdrawn from the sump 15 though the oil inlet 20extending into the sump. From the pump 18 the oil is conveyed upwardlythrough the interior of the housing 14 by a conduit 21 connecting theoutlet of the pump to the lower end of the tubular element 12. A portionof the oil flowing through the conduit 21 escapes through the outlet 22provided at the upper end thereof and is directed thereby over the motor2 for the purpose of extracting heat from the motor. This portion of theoil flows downwardly over the motor and most or all of the warmed oilreturns to the sump through the lower tubular element 13 whichcommunicates with the interior of the housing 14 although some of it mayflow through the lower stator slots and back to the sump,

The upper tubular element 12 is so connected to the conduit 21 that allof the oil which does not escape through the outlet 22 flows upwardlythrough this tubular element and onto the side walls 25 and 26 of thecasing 1. In order to distribute the oil emerging from the upper tubularelement 12 evenly over relatively large area of the casing side walls,there is provided an oil distribution means in the form of baffies 28and 29 suitably secured to the upper bracket 7 and having relativelywide discharge ends extending substantially the length of the side walls25 and 26 of the casing 1. Between the discharge ends 30 of the baffles28 and 29 and the side walls 26 and 25, there are provided screensindicated by the numeral 34 which lie flat against the side walls asindicated in Fig. 3 and which due to their construction offer a pluvgatented Oct. 6, 1959 3 over the baflle sections 28 and 29 filtersdownwardly and uniformly over the side walls 25 and 26 of the casing.This oil cooled by contact with the relatively cool side walls thenreturns to the oil sump i5. In order to provide a positive transfer ofthe oil fro the outlet end of the upper tubular element 12 to the Walls25 and 26 or at least to the sections 28 and 29, the upper tubularelement 12 preferably has a closed top 35 and two small horizontalorifices 36 through which the oil is sprayed horizontally in thedirection of the casing side walls and beyond the aperture 9 provided inthe upper bracket 7.

During operation of the motor-compressor unit, the oil cooled as itflows down the casing side walls 25 and 26 mixes with the warmer oilreturning from the motor through the tubular element 13 before againbeing picked up for recirculation through the oil inlet tube 20. a Inorder to assure a thorough mixing of the two portions beforerecirculation and particularly to prevent direct circulation of hot oilfrom the tubular element 13 to the inlet 29, there is provided apartition element 38 between the tubular element 14 and the oil inlet20. This partitioning element preferably completely surrounds the oilinlet 20 and in eifect divides the sump into two portions, that is areturn portion and a reservoir or supply portion. To supply oil to theoil inlet 20, one or more apertures 39 are employed on the side of thepartition away from the tubular element 13. By this arrangement all ofthe oil entering the supply portion within the partition 38 forcirculation through the motor first flows around the partition and in sodoing mixes with the cold oil from the casing walls.

While the invention has been described with reference to the particularembodiment thereof, it will be understood that modifications may be madeby those skilled in the art without actually departing from theinvention and it is intended, therefore, in the appended claims to coverall such variations as come within the true spirit and scope of theinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:'

1. A hermetic compressor comprising a sealed casing having an oil sumpat the bottom thereof, a horizontal axis motor-compressor unitspring-suspended within said casing above said sump; said unit includinga cylindrical housing enclosing one end of said motor, means forlimiting tilting of said unit within said casing comprising upper andlower brackets each having an aperture therein and being secured to saidcasing above and below said housing and upper and lower tubular elementsrespec tively secured to the top and bottom sides of said housing andloosely extending into said apertures; and a motor cooling and oilcooling system including an oil inlet communicating with said sump, anoil pump, a conduit extending through said housing and connecting saidpump with said upper tubular element, said conduit having an outletwithin said housing for directing lubricant into cooling contact withsaid motor, said lower tubular element communicating with the interiorof said casing and said sump to provide a return for oil from saidcasing to said sump, said upper tubular element having an oil outlet atthe upper end thereof, means for distributing oil from said outlet insaid upper tubular element over the walls of said casing comprising asloping baflie extending substantially from said upper tubular elementto the walls of said casing, a screen disposed between the extremity ofsaid baffie and said casing for distributing the oil from said uppertubular element over a substantial portion of the walls of said casing,and a partition in said sump between said lower tubular element and saidoil inlet for preventing direct flow of oil from said lowertubularelement to said oil inlet.

'2. A hermetic compressor comprising a sealed casing having an oil sumpat the bottom thereof, a horizontal axis motor-compressor unitspring-suspended within said casing above said sump; said unit includinga cylindrical housing enclosing one end of said motor, means forlimiting tilting of said unit within said casing comprising upper andlower brackets each having an aperture therein and being secured to saidcasing above and below said housing and upper and lower tubular elementsrespectively secured to the top and bottom sides of said housing andloosely extending into said apertures; and a motor cooling and oilcooling system including an oil inlet communicating with said sump, anoil pump, a conduit extending through said housing and connecting saidpump with said upper tubular element, said conduit having an outletwithin said housing for directing lubricant into cooling contact withsaid motor, said lower tubular element communicating with the interiorof said casing and said sump for returning said motor cooling oil tosaid sump, said upper tubular element having an oil outlet adjacent theupper end thereof, means for distributing oil from said outlet in saidupper tubular element over the walls of said casing comprising a slopingbaflle extending from said upper bracket to the side walls of saidcasing, a screen disposed between the extremity of said baffle and saidcasing for distributing the oil from said upper tubular element over asubstantial portion of the walls of said casing and a partition in saidsump surrounding said oil inlet, said partition having passages in theside thereof opposite the side facing said lower tubular element wherebyhot oil returning from said motor is mixed with cooled oil flowing downthe walls of said casing before passing through said passages to saidoil inlet.

3. A hermetic compressor comprising a sealed casing having an oil sumpat the bottom thereof, a horizontal axis motor-compressor unitspring-suspended within said casing above said sump; said unit includinga cylindrical housing enclosing one end of said motor, means forlimiting tilting of said unit within said casing comprising upper andlower brackets each having an aperture therein and being secured to saidcasing above and below said and loosely extending into said apertures;and a motor cooling and oil cooling system including an oil inletcommunicating with said sump, an oil pump, a conduit extending throughsaid housing and connecting said pump with said upper tubular element,said conduit having an outlet within said housing for directing oil intocooling contact with said motor, said lower tubular element opening intosaid casing and said sump for returning oil from said casing to saidsump, said upper tubular element having an oil outlet adjacent the topthereof, means for distributing oil from said upper tubular elementoutlet over the walls of said casing comprising a sloping baflieextending from said upper bracket to the side walls of said casing, ascreen disposed between the extremity of said baffle and said casing andhaving one side in contact References Iited in the file of this patent VUNITED STATES PATENTS

